In a developing country . . . when you talk about taking water away, you're talking about having a large impact on economic growth, on job creation, on our ability to fight poverty, and so on.

 Brian Van Wilgen, South African ecologist

South Africa is running out of water. All of South
Africa draws its water from rivers that flow out of just a few mountain
ranges. Sparse rainfall on the mountains used to be channeled through rivers
and streams to the lowlands. Before European colonists arrived, grasslands
and

A team clears a stand of trees in South Africa.

fynbos vegetation, unique to the Cape of Good Hope, dominated lowland regions.
But when the colonists arrived, preferring the forested landscapes of home,
they planted non-native trees, mostly pine and eucalyptus, which have now
invaded the mountainous regions and are soaking up billions of gallons of
water that once filled streambeds. Earth on Edge introduces us to
the surprising sight of environmentalists with chainsaws  people who are
trained by the government to cut down the invasive species and restore the
precious water that flows from the mountains to the rivers. But some estimate
it will cost 30 million rand (roughly US $238.5 million) per year for 20
years to keep the water flowing. Current freshwater restoration projects
in many parts of the world cost billions of dollars each, the price to restore
what would be free if we had only used it sustainably.